Question

Bone has a Young’s modulus of about

1.8 × 10^10 Pa . Under compression, it can

withstand a stress of about 1.53 × 108 Pa before breaking.

Assume that a femur (thigh bone) is 0.5 m

long, and calculate the amount of compression

this bone can withstand before breaking.

Answer in units of mm

Answer 1

4.25 mm

Step-by-step explanation:

σ = E ∙ ∆L/L₀

where σ is stress,

E is Young's modulus,

and ∆L/L₀ is strain (∆L is the deflection, L₀ is the initial length).

Plugging in values:

1.53×10⁸ Pa = (1.8×10¹⁰ Pa) ∆L / (500 mm)

∆L = 4.25 mm